Patent GB-788700-A (GB)
Title: Steroid compounds and preparation thereof
IPC: C07J71/00
Filed: 1956-03-22
Abstract: The invention comprises D 4-pregnene-11b , 17a  - diol - 3,20 - dione - 16b ,21 - oxide, and D 5 - pregnene - 11b ,17a  - diol - 3,20 - dione-16b ,21 - oxide - 3,20 - bis - ethylene ketal, and a process which may commence at any stage in the following synthesis: D 5,16-pregnadiene-11b ,21 - diol - 3,20 - dione - 21 - alkanoate 3,20-bis-alkylene ketal is reacted with osmium tetroxide in an inert organic solvent with the subsequent decomposition of the osmate complex under alkaline conditions to form D 5-11b ,16a ,17a ,21 - tetrol - 3,20 - dione 21 - alkanoate 3,20-bis-alkylene ketal, which is reacted with an alkyl or aryl sulphonyl halide to form D 5-pregnene - 11b ,16a ,17a ,21 - tetrol - 3,20 - dione 16-alkyl (or aryl) sulphonate 3,20-bix-alkylene ketal, this compound is heated in a solution of an alcoholic alkali metal hydroxide to form D 5 - pregnene - 11b ,17a  - diol - 3,20 - dione-16b ,21 - oxide 3,20 - bix - alkylene ketal, which is then hydrolysed with aqueous mineral acid to form D 4-pregnene-11b ,17a -diol-3,20-dione-16b ,21-oxide.  The hydrolysis with aqueous mineral acid may be carried out in a step-wise manner, e.g. with sulphuric acid.  The above synthesis may be modified in that the D 5 - pregnene - 11b ,17a  - diol - 3,20 - dione-16b ,21 - oxide 3,20 - bis - alkylene ketal is obtained by reacting D 5 - pregnene - 17a  - ol-3,11,20 - trione - 16b ,21 - oxide 3,20 - bisalkylene ketal (which is obtainable from D 5-pregnene - 17a  - ol - 3,11,20 - trione - 16b ,21-oxide) with lithium aluminium hydride.  The alkylene ketal groups may be ethylene or propylene ketal groups, and the 21-alkanoate group may be an acetate, propionate or butyrate group.  The examples illustrate both the processes referred to above, the 3,20-alkylene ketal groups being ethylene ketal groups and the 16-sulphonate group being a methanesulphonate group.  The examples illustrate a step-wise and simultaneous acid hydrolysis of the ethylene ketal groups in the 3- and 20-positions of D 5 - pregnene - 11b ,17a  - diol-3,20 - dione - 16b ,21 - oxide 3,20 - bis - ethylene ketal, D 4 - pregnene - 11b ,17a  - diol - 3,20-dione - 16b ,21 - oxide 20 - ethylene ketal being an intermediate in the step-wise acid hydrolysis. Dinitrophenylhydrazine derivatives of D 4-pregnene - 11b ,17a  - diol - 3,20 - dione - 16b ,21 - oxide are referred to, and in an example D 4-pregnene-11b ,17a  - diol - 3,20 - dione - 16b ,21 - oxide 3-(2,4-dinitrophenylhydrazone) is prepared.  Starting compound. D 5-Pregnene-17a -ol-3,11,20-trione-16b -21-oxide 3,20-bis-ethylene ketal is prepared by treating D 5,16-pregnadiene-21-ol - 3,11,20 - trione 21 - acetate 3,20 - bisethylene ketal with osmium tetroxide to form an osmate ester, hydrolysing the ester under alkaline conditions to form D 5-pregnene-16a , 17a ,21 - triol - 3,11,20 - trione 21 - acetate 3,20-bis-ethylene ketal, sulphonating this ketal with methanesulphonyl chloride to form D 5-pregnene - 16a ,17a ,21 - triol - 3,11,20 - trione 16-methanesulphonate 21-acetate 3,20-bis-ethylene ketal, and hydrolysing the methanesulphonate with alcoholic potassium hydroxide solution.